‘Buffy’ Star Nicholas Brendon’s Cause of Death Revealed

Nicholas Brendon’s cause of death has been confirmed by the Putnam County Coroner's office.

Brendon’s loved ones announced the “Buffy the Vampire Slayer” actor’s passing on March 20. He was 54.

In a report obtained by People magazine, coroner Todd Zeiner states Brendon’s death was ruled natural with the cause listed as atherosclerotic and hypertensive cardiovascular disease.

The American Heart Association describes atherosclerotic disease as plaque buildup in arterial walls. The Cleveland Clinic lists hypertensive disease as unmanaged high blood pressure that can cause issues like the heart muscle thickening or heart failure.

Contributing factors to Brendon’s death included acute pneumonia and previous myocardial infarction (heart attack).

The "mechanism of death” was determined to be a 90 percent blockage of his right coronary artery.

Zeiner added that there were no signs of foul play, writing that Nicholas’ friend Theresa Fortier called 911 from the actor’s residence.

"Theresa stated the decedent had been having a persistent cough and had been self medicating with over the counter medications,” Zeiner wrote. "He had been complaining about chest pain. She recommended a hospital, but he declined. He was a longtime smoker and was apprehensive about going due to his recent back surgery. She advised he had a recent heart attack several years ago, but he declined any further treatment at that time.”

Zeiner said during the autopsy they found Brendon had a "markedly enlarged heart, severe stenosis of the right coronary artery, moderate stenosis of the left anterior descending and left circumflex arteries, acute pneumonia and inflammation of the small bowel. The small bowel inflammation is most likely secondary to ischemic changes related to the cardiogenic shock.”

The coroner noted that videos Brendon had filmed at his home prior to his death showed the star was “markedly coughing” and had a “raspy voice” and "provided a basis for his declining health.”

Toxicology results are still pending.